This invention relates to foods which have been formulated to contain soluble high amylose starch. The starch is selected from: a spray-dried, non-granular, high amylose starch, characterized in that the starch is substantially non-crystalline, substantially non-retrograded, and fully predispersed; a spray-dried, uniformly gelatinized, high amylose starch in the form of granular indented spheres, with at least a majority of the granules being whole and unbroken, these starch granules being in the form of loosely-bound agglomerates or individual granules; and an enzymatically debranched, gelatinized starch, comprising at least 40% amylose. These starches are soluble in hot or cold water and cooking is not required to formulate foods containing these starches.
As used herein, "soluble" means that the high amylose starches in powdered form may be readily hydrated and dispersed in hot or cold water or other aqueous medium to provide a starch solution in the form of a complex colloidal dispersion, rather than a true molecular solution.
Native high amylose starches are corn starches from hybrid varieties of corn which contain at least about 40% amylose. In contrast, ordinary corn starch typically contains about 28% amylose. As used herein, "high amylose starch" includes the starch from hybrid strains of corn, as well as other starches which contain added isolated amylose, or which have been enzymatically debranched to yield a starch comprising at least about 40% amylose. This debranched starch may comprise both native long chain amylose and short chain amylose generated by debranching amylopectin molecules.
Because amylose, a linear polymer, readily aligns or associates through hydrogen bonding, starches containing large amounts of amylose will form more rigid gels and stronger, tougher films, and will provide surfaces having reduced air, water and oil absorption and migration in food applications, relative to ordinary starches which typically contain much less than 40% amylose. Other advantages include improved binding properties where the starch primarily functions as an adhesive and the related property of improved cling or adhesion between dissimilar food substrates. The unique binding, structural and textural characteristics of the high amylose starches make them useful as protein replacers, especially caseinate replacers, in foods.
A process for improving deep fried potato products, including potato chips, french fried potatoes, and specialty potatoes, wherein the potatoes are coated with an aqueous dispersion of a high amylose starch prior to frying, is disclosed in U.S. Pat. No. Re. 27,531, reissued Dec. 12, 1972, to Murray, et al. The potato products are characterized by a high degree of crispness which is retained for long periods, superior strength and rigidity, resistance to breakage without undesirable toughness, reduced absorption of oil during frying, reduced variation in the amount of oil absorption, little color variation, and excellent flavor and storage characteristics.
An improved batter mix for preparing coated prefried, microwavable-foods, wherein the batter contains, on a batter mix solids basic, about 50-80% of a high amylose flour containing at least 50% amylose, is disclosed in U.S. Pat. No. 4,595,597, issued Jun. 17, 1986, to Lenchin, et al. The batter containing the high amylose flour provides a crisp and appealing outer coating in foods formulated for use in the microwave oven. The high amylose flour batter also provides good adhesion and cohesion to the food and acceptable color.
A batter for Use on frozen, prefried, convenience foods, wherein the batter comprises, on a batter dry mix basis, about 50 to 80% of a high amylose flour containing at least 50% amylose, is disclosed in U.S. Pat. No. 4,529,607, issued Jul. 16, 1985, to Lenchin, et al. The batter provides improved crispness in the food coating after conventional cooking.
Improved pet foods, of the semi-moist variety, wherein starches, including modified high amylose corn starch, are employed as dough modifiers, is disclosed in U.S. Pat. No. 4,251,556, issued Feb. 17, 1981, to Burkwall, Jr., et al. The starch advantageously replaces, in part, caseinates as a binder in the pet food.
A formulated french fried potato product produced from dehydrated potato granules or flakes with a binder, comprising a high amylose starch and a cold water dispersible starch or gum, is disclosed in U.S. Pat. No. 3,987,210, issued Oct. 19, 1976, to Cremer. The high amylose starch component, preferably containing at least about 35% amylose, functions by retrograding to form a film or oil barrier on the french fried dough so that the dough does not absorb large quanties of frying oil. The high amylose starch also adds strength to the french fried product during and after frying. Useful high amylose starches include granular or ungelatinized high amylose starch containing at least 55% amylose, and, optionally, ester and ether derivatives of the starches; and amylose obtained by fractionating starch and derivatives thereof.
Certain high amylose starches and starch blends have been successfully employed as caseinate replacers in imitation cheeses. The starches useful as caseinate replacers differ from starches and flours which have been used in various cheese products as thickeners, binders, and the like. Unlike the thickeners and binders, the caseinate replacement starches provide the texture, thermoreversibility (melt) and emulsification characteristics of caseinates in imitation cheeses. A starch characterized by thermoreversibility forms a gel when a cooked aqueous starch dispersion is cooled, which gel melts upon reheating and sets again upon cooling.
U.S. Pat. No. 4,608,265, issued Aug. 26, 1986, to Zwiercan, et al., discloses an imitation cheese, wherein 25 to 50% of the caseinate as replaced by pregelatinized modified high amylose starches, preferably converted and derivatized. The starch has an amylose content of at least 40% and is preferably selected from the group consisting of derivatized starch, converted starch, converted and derivatized starch and crosslinked starch. The high amylose starch may be mixed with up to 80%, by weight, of a low amylose starch (leas than 40% amylose). U.S. Pat. No. 4,695,475, issued Sep. 22, 1987, to Zwiercan, et al., discloses an imitation cheese wherein up to 100% of the caseinate is replaced by a pregelatinized, converted and derivatized high amylose starch.
The formulation of foods with the high amylose starches known in the art disadvantageously requires much higher cooking temperatures than the temperatures required for cooking other starches. Due to the highly bonded linear structure of high amylose starches, full and effective gelatinization of high amylose starches typically requires cooking temperatures of about 154.degree.-171.degree. C., when the starch contains about 70% amylose. Thus, to obtain high amylose starches, or foods containing such starches, which are soluble in hot or cold water, super atmospheric cooking temperatures are usually required. Furthermore, traditional methods of starch pregelatinization typically produce high amylose starches that are retrograded, or have crystalline portions or are otherwise incapable of full dispersion, or are degraded such that their functional benefits are substantially reduced.
For example, a method for preparing drum-dried, non-granular, pregelatinized isolated potato amylose is described in U.S. Pat. No. 3,086,890, issued Apr. 23, 1963, to A. Sarko, et al. The starch slurry is heated to a temperature from just above boiling to 191.degree. C. (375.degree. F.) and a pressure of about 5 to 140 psi for 1 to 60 minutes. It is then drum-dried at 110.degree.-200.degree. C. (230.degree.-392.degree. F.) for 40-75 seconds and the resulting sheet is pulverized to a dry, porous, white fluffy powder. Sarkols assignee subsequently disclosed in U.S. Pat. No. 3,515,591, issued Jun. 2, 1970, to Feldman, et al., that the product of Sarko's drum-drying method slowly retrogrades upon storage and is unsuited for use in packaged foods. The Feldman patent teaches a different method for preparing cold water soluble high amylose starch which disadvantageously requires the high amylose starch to be solubilized at 140.degree.-170.degree. C. and mixed with an aqueous suspension of gelatinized starch before drying.
In the alternative, high amylose starches have been modified by derivatization and conversion to enhance their gelatinization and dispersibility characteristics. The use of these "modified starches" is undesirable in food products that are advertised as "natural" products. Gel strength and water resistance qualities of the modified high amylose starches also are reduced in proportion to the amount of modification.
Accordingly, there is need for foods containing soluble high amylose starch which can be formulated without cooking or without using a chemically modified starch, and can be prepared by dispersing the soluble high amylose starch in hot or cold water, before, during, or after food formulation.